What causes gnarls on trees? What are these knots composed of? Example: A huge knot around the base of an oak tree.

Backyard Expert - Cathy Nordstrum Some trees just naturally have gnarly areas of bark where a branch meets the trunk, as with the cocoa tree. On trees not usually gnarled, however, the gnarled area is callus tissue the tree grows where it has experienced some kind of environmental stress. Such an area at the base of a tree could have been caused by a lightning strike, loss of bark due to insects or disease, or even an early injury when the tree was but a sapling.

Trees with gnarls usually can thrive and prosper as long as the tree can repair itself before being damaged further. A sign of age often lending an air of romantic character, gnarly trees capture our imaginations with their rugged good looks. Thanks for sending in this perfectly gnarly question!

Followers

About Me

Born the night Japan attacked Pearl Harbour / became a man the day I harnessed a team of horses for my grandfather / hitch-hiked across Canada and back / married my high school sweetheart / spent 41 years in newspaper publishing / birdwatcher for the past 26 years / take a canoe over a car any day / proud father and grandfather / lifelong hedonist